Land developers are becoming more interested in trying to save trees on the land they are developing. In fact, some communities, such as Austin Texas, have an ordinance protecting trees 19 inches in diameter or larger. Since such trees are usually in the way of the planned construction, they must be moved to another location on the site or elsewhere. For the trees to have a reasonable chance of surviving, a substantial root ball must be moved with the tree.
Mechanical devices for excavating trees have existed for decades. However, these devices are limited in application, as they may conventionally only excavate small trees and shrubs. Larger trees, having trunks greater than 15 inches in diameter, commonly require a more manual method for excavation called "round-ball" or boxing." In this method, a large trench several feet in width and depth is be excavated around the tree. Long pipes or wooden members are then horizontally driven at the bottom of the trench from one side of the tree to another, forming a support framework underneath the tree. Cranes may then lift this framework and the tree out of the ground for subsequent transplantation. The method is very tedious and labor intensive, requiring the aid of multiple workers and tools, and is particularly disfavored during mild flooding, on sloping terrain, or with medium rocky or clay-type soils. Thus, strides were taken to automate the process of large tree excavation.
Previous tree moving equipment such as the DeHaan device, U.S. Pat. No. 4,226,033, the Lemond device, U.S. Pat. No. 4,286,398, the Newman device, U.S. Pat. No. 4,301,605, the Stocker device, U.S. Pat. No. 4,341,025, the Dahiquist device, U.S. Pat. No. 4,403,427, the Weeks device, U.S. Pat. No. 5,081,941, and the Stevens device, U.S. Pat. No. 5,485,691, employed a plurality of blades that severed the root ball from the ground and formed a supporting structure for the root ball and tree as it was lifted out of the ground and moved to its new location. The blades were guided into the ground by various types of guide members that engaged the blade over a substantial portion of their length. This resulted in significant structure high above the ground. This structure is a disadvantage to utilizing the prior art, such that trees with low limbs frequently require the limbs to be removed in order be transplanted.
The Korenek tree transplanter, U.S. Pat. No. 4,658,518, attempted to alleviate this problem, but it also has its disadvantages. Use of the Korenek equipment can be limited when utilized on terrain that is not level because the mast requires the ring assembly, tree and root ball to be raised vertically. The problem may become evident when the apparatus is utilized on terrain having more than minimal slope, such as that exceeding 10 degrees. Many applications require the transplantation of a tree either from or to a terrain that has a significant slope, such that the blades of the previous equipment might not be properly aligned with the axis of the tree, thereby resulting in excavating a root ball insufficient to protect the tree and ensure successful transplantation. Since the ring structure and blades of the prior art are set in a given plane in relation to the terrain, the Korenek equipment may not allow the excavation of a tree and adequate root ball from severely sloped terrain, such as the side of a mountain. Further problems may arise with the Korenek equipment when the tree to be excavated and has a crooked trunk or significant branches which the mast would interfere with, such that in positioning the transplanting apparatus around the tree, the trunk may force the misalignment of the ring structure and blades in relation to the root ball, resulting in the excavation of an inadequate or asymmetrical root ball, and thereby sacrificing the health of the tree and decreasing the likelihood of successful transplantation.
Since the Korenek apparatus includes a mast on which a ring structure vertically raises and lowers in relation to the ground. The mast stands in a strictly vertical plane and may interfere with the limbs of large trees, possibly injuring the tree limbs or requiring the removal of several tree limbs in order to accurately position the apparatus around the tree. Further, this problem makes such devices particularly disadvantageous for use in nurseries where it is desirable to plant and cultivate trees as closely as possible to utilize the available land most efficiently. Because of the space required for maneuvering and positioning conventional devices to remove such trees, the trees must be planted a greater distance apart than would generally be desirable from the standpoint of utilizing available space in the most efficient manner possible.
Additionally, those skilled in the art have learned that the mast arrangement is often not strong or rigid enough to use the apparatus with large trees, such that additional braces have been attached between the mast and various points on the ring structure. These additional supports may also interfere with the limbs of the tree to be excavated, resulting in the need to again remove several limbs prior to excavation. To desirably position the ring assembly of the Korenek device for a tree excavating operation, the lower end of the mast is closely adjacent the ground surface. This close spacing e.g., approximately 8 inches, presents ground clearance problems when using the equipment, particularly in muddy environments.
Moreover, once a tree is excavated with the Korenek equipment, the weight of the excavated tree bears substantially upon the mast. To counteract the moment about the mast created by the excessive weight of the tree, a particular prime mover must be selected to prevent the mast from breaking and to prevent the excavated tree from falling backwards to the ground. This limitation in selecting a prime mover of appropriate weight to prevent such malfunction is particularly disfavored to those skilled in the art, since many applications have limitations in the availability of prime movers of various weights.
The Korenek apparatus is also susceptible to malfunctions attributed to wear and fracture of the blade guides which guide the blades into the ground. The guides in the Korenek apparatus receive excessive loading from the blades, a problem intensified by the minimal contact area between the blades and the guides. This loading creates excessive wear on the guides, resulting in the failure of the guides or blades, and thereby driving up maintenance requirements of the apparatus, decreasing the reliability of the device, and ultimately increasing operating costs of the device. The guides also provide no effective means for removing debris that becomes lodged between the guides and the blades during use, a factor that leads to further malfunction or fracture of the apparatus. Also, as the Korenek transplanting apparatus is repeatedly used and the force of the blades on the guides and debris accumulates between the guides and the blades, significant wear is effected on the guides, such that the engagement of the guides and the blades is lessened, thereby preventing the blades from being accurately driven into the ground. This also results in the inadequate excavation of the root ball and diminishes the likelihood of tree survival.
Finally, utilization of the Korenek tree transplanter can be a tedious process, requiring multiple bolting and unbolting of the ring sections to and from one another. While tree excavating apparatus are often utilized in the construction and nursery industries where time is of the essence, a tedious procedure is not cost effective. Utilizing this equipment requires the additional utilization of multiple tools and several people, thereby increasing both the complexity, execution time and cost of excavating a single tree.
It is highly desirable to provide a tree excavating and transplanting apparatus that is easily operated and highly reliable, that may be utilized on terrain of even the most severe slope with trees having severely crooked trunks, that requires little time and minimal trimming to execute the excavation of trees of any size, and that overcomes the wear and maintenance problems inherent in the prior art.